Hard start kit for multiple replacement applications

ABSTRACT

A hard start capacitor replacement unit has a plurality of capacitors in a container sized to fit in existing hard start capacitor space. The capacitors are metallized film capacitors wound in a single cylindrical capacitive element. The container has a common terminal and capacitors value terminals for the plurality of capacitors, which may be connected singly or in combination to provide a selected capacitance. An electronic or other relay connects the selected capacitance in parallel with a motor run capacitor. The hard start capacitor replacement unit is thereby adapted to replace a wide variety of hard start capacitors.

CLAIM OF PRIORITY

This application is a continuation of and claims priority under 35U.S.C. § 120 to U.S. application Ser. No. 14/299,111, filed on Jun. 9,2014, which is a continuation of and claims priority under 35 U.S.C. §120 to U.S. application Ser. No. 13/826,689, filed on Mar. 14, 2013, nowU.S. Pat. No. 8,885,318 which is a continuation of and claims priorityunder 35 U.S.C. § 120 to U.S. patent application Ser. No. 12/927,476filed on Nov. 15, 2010, now U.S. Pat. No. 8,456,795, which claimsbenefit of priority under 35 USC § 119(e) to U.S. ProvisionalApplication Ser. No. 61/281,141, filed on Nov. 13, 2009, the entirecontents of which are hereby incorporated by reference.

TECHNICAL FIELD

The invention herein relates to a hard start capacitor replacement unitthat is adaptable in the field for replacing any one of a plurality ofmultiple hard start modules.

BACKGROUND

Single phase induction motors of the type commonly used with airconditioner and cooling equipment compressors generally require sometype of auxiliary start capacitor for starting the motor. If the motoris a permanent split capacitor motor, i.e. one that has a run capacitorpermanently connected across the run and start windings the motor, thestart capacitor is connected in parallel with the run capacitor. Thestart capacitor, also sometimes referred to as a “hard start capacitor,”is connected for a short period of time to start the motor, and thestart capacitor is disconnected from the motor near or at the time themotor achieves its run speed. This time is generally on the order of50-100 milliseconds. Therefore, the start capacitor is wired in serieswith contacts for disconnecting it. The contacts can be a part of apotential or control relay, or an electronic relay.

If the start capacitor or the relay controlling it fails, the motor willnot start. It is then necessary to replace the start capacitor andcontrol relay, and this generally must be accomplished at the site ofthe motor. For air conditioners and other cooling equipment, this sitecould be a home, an office, a warehouse or factory, store, or any otherbuilding. This complicates the task of replacing the start capacitor andits connecting relay, in that a wide variety of brands and sizes of airconditioning and cooling units are in use, and these units use startcapacitors having a variety of capacitances. Therefore, unless arepairman has a replacement hard start kit available with the correctlysized start capacitor, the repairman cannot complete repair withoutreturning to a shop or parts distributor that has an inventory of hardstart capacitor replacement parts.

Having to return to a shop or parts distributor in order to obtain thenecessary materials to complete a repair is inefficient and timeconsuming and also delays the time that the customer's cooling systemcan be returned to operation.

Therefore, it would be advantageous if a repairman could carry one hardstart replacement unit that is adaptable to many air conditioning units,cooling units, or other equipment utilizing single phase motorsrequiring a start capacitor, so that the repairman could adapt the hardstart replacement unit to the requirements at hand and complete therepair in a timely manner.

SUMMARY

It is a principal object of the invention herein to provide a hard startcapacitor replacement unit adaptable to more than one motor.

It is an additional object of the invention herein to provide a hardstart capacitor replacement unit with selectable capacitance.

It is also an object of the invention to provide a hand start capacitorreplacement unit with circuit interruption protection.

It is a further object of the invention herein to provide a hard startcapacitor replacement unit that can be configured at a repair site toprovide a desired selected capacitance.

It is also an object of the invention herein to provide a hard startcapacitor replacement unit with at least four selectable capacitances.

It is another object of the invention herein to provide a hard startcapacitor replacement unit with selectable capacitance that mounts insubstantially the same space as an original start capacitor unit.

In carrying out the invention herein a hard start capacitor replacementunit is provided having a cylindrical container with a cover. Aplurality of capacitors are provided within the container, each of saidcapacitors having a capacitance value. The cover mounts a commonterminal electrically connected to common plates of each of saidplurality of capacitors. The cover also mounts a plurality ofcapacitance value terminals spaced apart from the common terminal andfrom each other, with each capacitance value terminal respectivelyconnected to a capacitor of a corresponding capacitance value. A relayhas a contact and means for opening and closing said contact in responseto voltage across start and run windings of a single phase electricmotor. Wire means are provided for connecting one side of the contact ofthe relay to one of the start and run terminals of the electric motor.Wire means are also provided for connecting the other side of thecontact of the relay to a cover terminal and for connecting anothercover terminal to the other of the start and run terminals of theelectric motor, at least one of the wire connections being to the commonterminal on the cover and the other wire connection being to acapacitance value terminal, such that at least one capacitor isconnected between the relay and the motor. The capacitance valueterminal is selected to connect a capacitor of the desired capacitancevalue. Jumper wires are connected between capacitance value terminals onthe cover to connect additional capacitors, in order to select a totaldesired capacitance value.

In other aspects of the invention, the capacitors are wound asindividual sections of one cylindrical capacitive element. Thecapacitors may be metallized polymer capacitors. The film may bepolypropylene with a zinc coating.

In another aspect of the invention, there are four capacitors within thecylindrical capacitor container. The values of the capacitors may beabout 48 microfarads, about 48 microfarads, about 88 microfarads andabout 112 microfarads, each having a corresponding capacitance valuecover terminal.

In additional aspects of the invention herein, the cover has fourcapacitive value terminals and a common terminal. The common terminal iscentered on the cover. The cover terminals are separated by insulatingbarriers. Jumper wires are provided to selectably connect capacitancevalue terminals.

In yet another aspect of the invention, the cover includes circuitinterruption protection.

In a further aspect of the invention, the relay is an electronic relay.The relay may also be a control or potential relay. The relay is sizedto be accommodated above the capacitor container within the projectedcylindrical envelope thereof. A cylindrical cap is received on thecapacitor container and extends therefrom to surround the relay andcover terminals. The cap is frictionally retained on the capacitorcontainer and may be removed to make connections to selected capacitancevalue cover terminals.

The foregoing and other objects and features of the invention hereinwill, in part, appear in the following detailed description of theinvention and claims, taken together with the drawings.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a hard start capacitor replacement unitaccording to the invention herein shown connected to a schematic motor;

FIG. 2 is an exploded perspective view of the hard start capacitorreplacement unit of FIG. 1;

FIG. 3 is a sectional view of the capacitor, capacitor container andcover of the hard start capacitor replacement unit of FIG. 1;

FIG. 4 is a schematic circuit diagram of the hard start capacitorreplacement unit of FIG. 1, shown connected to a motor;

FIG. 5 is a top view of the cover and cover terminals of the hard startcapacitor replacement unit of FIG. 1, showing the capacitors connectedto provide a first capacitance value;

FIG. 6 is a top view of the cover and cover terminals of the hard startcapacitor replacement unit of FIG. 1, showing the capacitors connectedto provide a second capacitance value;

FIG. 7 is a top view of the cover and cover terminals of the hard startcapacitor replacement unit of FIG. 1, showing the capacitors connectedto provide a third capacitance value;

FIG. 8 is a top view of the cover and cover terminals of the hard startcapacitor replacement unit of FIG. 1 showing the capacitors connected toprovide a fourth capacitance value; and

FIG. 9 is a schematic circuit diagram of another hard start capacitorreplacement unit according to the invention, shown connected to a motor.

The same reference numerals refer to the same elements throughout thevarious Figures.

DETAILED DESCRIPTION

With reference to FIG. 1, a hard start capacitor replacement unit 10 isshown, including a cylindrical capacitor container 12 and a cylindricalcap 14 fitted onto the container 12 and extending therefrom. Withreference to FIG. 2, the cap 14 may be removed from the container 12, toexpose the cover 16 of the container, an electronic relay 18, and wiremeans 20 providing desired electrical connections for the hard startcapacitor replacement unit 10 to a motor 60.

The container 12 is preferably 2½ inches in diameter with a length of 5¾inches and has a plurality of capacitors therein. In the embodimentshown and with reference to FIG. 3, four capacitors 22, 24, 26 and 28are provided within the container 12. Also in the embodiment shown, thecapacitors 22, 24, 26 and 28 are wound in a cylindrical capacitiveelement 30 having a common element terminal 32 at the bottom thereof andfour capacitor terminals 23, 25, 27 and 29 at the top thereof.

The capacitors of capacitive element 30 are preferably metallized filmcapacitors concentrically wound together as the cylindrical capacitanceelement 30. The film is preferably polypropylene metallized with zincand may be about 3.8 microns in thickness. This is an advantageous filmfor several reasons. First, start capacitors generally require a highercapacitance value than run capacitors, i.e., run capacitors generallyhave typical capacitance values in the range of about 15 to about 65microfarads, whereas start capacitors may have typical capacitancevalues up to about 300 microfarads. Such high start capacitance valueshave generally been achieved with electrolytic capacitors because300-microfarad capacitors with typical film thicknesses would be bulkyand require a large container that may not fit into the space providedin an air conditioning unit or the like. However, with recognition thata start capacitor is utilized for about one second or less as the motorstarts, it does not have to be rated at high voltage over a long periodof time. Therefore, a thin film may be used and the required capacitanceis attained in a reasonably sized capacitive element. A furtheradvantage is that the resultant metallized film capacitive element hasstable capacitance values over a relatively wide ambient temperaturerange, and also has a long service life.

The container is preferably filled with a dielectric fluid 34 and thecover 16 is provided with circuit interruption protection in the eventthe capacitive element fails, such as shown in FIG. 3 and described inU.S. Pat. No. 7,203,053. These are also advantages in fabricating thecapacitors 22, 24, 26 and 28 for the hard start capacitor replacementunit 10 from metallized film.

Although it is preferable to provide the capacitors in a cylindricalcapacitive element 30 wound of metallized film, the capacitors 22, 24,26, 28 may be individual wound capacitors having respective endselectrically connected to form a common terminal. The capacitive element30 may be provided with more or less than four capacitors if desired.The capacitors may also be provided as two or more capacitive elementseach having multiple capacitors.

It is also contemplated to make a hard start capacitor replacement unitwith a single multiple value electrolytic capacitor or multipleelectrolytic capacitors that may be connected to provide selectabletotal capacitance values. However, according to present electrolyticcapacitor technology, the container for such a capacitor or capacitorswould necessarily be larger than the container for a metallized filmcapacitive element and the capacitance value would not be as stable overambient temperature ranges.

In the hard stand capacitor replacement unit 10 shown and describedherein, capacitor 22 has terminal 23 and preferably has a capacitance of48 microfarads. Capacitor 24 has terminal 25, and also has a capacitancevalue of 48 microfarads. Capacitor 26 has capacitor terminal 27, and hasa value of 88 microfarads, and capacitor 28 has capacitor terminal 29and has a value of 112 microfarads.

As perhaps as best seen in FIGS. 5-8, the cover 16 mounts a common coverterminal 40 in the center thereof, and mounts capacitance valueterminals 42, 44, 46 and 48 spaced apart from the common cover terminal40 and from each other. The common cover terminal 40 is connected tocommon element terminal 32 of the capacitive element 30 and thereby toeach of the capacitors 22, 24, 26 and 28. The capacitance value coverterminal 42 is connected with the terminal 23 of capacitor 22 and thecapacitance cover terminal 44 is connected with the capacitor terminal25 of capacitor 24. The capacitance cover terminal 46 is connected withthe capacitor terminal 27 of capacitor 26 and capacitance value coverterminal 48 is connected with the capacitor terminal 29 of the capacitor28. Therefore, the capacitance values of the capacitors 22, 24, 26, 28are respectively available for wire connections at the correspondingcapacitance value cover terminals 42, 44, 46, 48 on the cover 16 ofcontainer 12.

A cover insulation barrier 50 is also mounted to the cover 16 to betterisolate the cover terminals. The cover insulation barrier 50 has acylindrical portion 52 surrounding the common cover terminal 40 and hasradial extending fins 54-58 that separate the other capacitance valuecover terminals. An extra fin is shown, which would insulate another oneor two cover terminals if an additional one or two capacitors wereprovided.

With reference to FIG. 4, a schematic of the operation of the startcapacitor replacement unit 10 is shown. The electronic relay 18 hasexternal terminals that accept wire termination clips, so that wireconnections can be made between the common cover terminal 40, and thecapacitance value cover terminals 42, 44, 46 and 48, as well as with thestart and run terminals 62 and 64 of a motor 60. External terminals T-1and T-2 of electronic relay 18 are internally connected with contacts 70and 72 that may be closed by a contact bar 74, all schematically shown.The electronic relay 18 also has external terminal T-5, and theelectronic relay 18 has circuitry indicated at 76 that monitors thevoltage and the dv/dt between terminals T-2 and T-5 and controls theopening and closing of the contacts 70 and 72 in response thereto.Terminals T-2 and T-5 are connected to the start and run terminals 62and 64 of compressor motor 60 by wires 20, so that the electronic relayis monitoring the voltage across the start and run windings. TerminalT-5 may also be connected between the start and run windings of motor60. When the contacts 70 and 72 are closed, the electronic relay 18connects the selected ones of the capacitors 22, 24, 26 and 28 acrossthe terminals 62 and 64 in parallel with the run capacitor 66 to assistin starting the motor. A bleeder resister 78 discharges the capacitor(s)when contacts 70, 72 are open. A suitable electronic relay is availablefrom Zhejiang Hongli Electric Co., Part No. HLR3800-6AM1D.

With reference to FIG. 9, the hard start capacitor replacement unit 10may also be used with a control or potential relay 90 as shown in theschematic. The relay contacts 92 and 94 are closed by contact bar 74 toconnect selected ones of capacitors 22, 24, 26, 28 across run terminals62, 64 of motor 60, and contacts 92, 94 are opened by coil 96 when themotor 60 starts. Bleeder resister 98 is provided to bleed off thecapacitor charge when the contacts 92, 94 are open.

It will also be appreciated that although the capacitors of the hardstart unit 10 are shown connected across motor terminals 62, 64, thepurpose of this connection is to connect the capacitors in parallel withthe motor run capacitor of the motor, and any connection thataccomplishes this is suitable.

In FIG. 4, the capacitors 22, 24, 26 and 28 are connected as also shownin FIG. 8, in which a first wire 80 connects T-1 of the electronic relaywith the cover capacitance value terminal 48, which selects 112microfarads of capacitance value. Jumper wire 82 between capacitancevalue terminals 48 and 46 connects an additional 88 microfarads ofcapacitance value into the circuit. Wire 88 connects the common terminal40 to terminal T-5 of the electronic relay 18. Jumper wire 84 connectingcapacitance value cover terminal 46 and capacitance value cover terminal44 connects a further 48 microfarads into the circuit. Thus, in theconfiguration shown in FIGS. 4 and 6, a total capacitance of 248microfarads is provided to start the motor 60 when the contacts of theelectronic relay 18 are closed.

It will be appreciated that a variety of capacitance values may beselected by connecting various ones of the capacitance cover terminalsto each other. Some preferred connections are shown in FIGS. 5-8. FIG. 5shows connection of capacitor 28 by wire 80 at cover terminal 48providing 112 microfarads, which is suitable for use where capacitancevalues in the range 108-130 microfarads are desired for the motor start.FIG. 6 shows connection of capacitors 26 and 28 by jumper wire 82 atcover terminals 46 and 48 providing 200 microfarads of capacitancevalue, which is suitable for desired capacitance values in the range of189-227 microfarads. FIG. 7 shows all of the capacitors 22, 24, 26, 28connected into the circuit at cover terminals 42, 44, 46 and 48 byjumper wires 82, 84 and 86 to provide a total 296 microfarads, which issuitable for use in applications requiring capacitance values in therange of 270-324 microfarads. FIG. 8 shows connection of capacitors 28,26 and 24 by jumper wires 82 and 84 providing 248 microfarads, for usewith applications requiring capacitance values of 233-280 microfarads.

If desired, the total capacitance values connected into the circuit canbe further refined with possible capacitance values of 48 microfarads,88 microfarads, 96 microfarads, 136 microfarads, 160 microfarads, 184microfarads and 208 microfarads, being available in addition to the 112microfarads, 200 microfarads, 240 microfarads and 296 microfaradsconfigurations shown above.

Once the desired capacitance value is selected by placing appropriatejumper wires on the cover terminals, the cap 14 may be fitted over thecontainer 12, to surround the cover terminals and electronic relay 18.The hard start capacitor replacement unit 10 has a suitable size andshape to be accommodated in the space provided for the original startcapacitor, so the hard start replacement unit 10 is readily accepted formounting in existing equipment.

As a result of the foregoing, a repairman can carry the hard startcapacitor replacement unit 10 to repair site with confidence that afailed start capacitor unit can be replaced without need to return to ashop or parts distributor in order to complete the repair.

Accordingly, a hard start capacitor replacement unit has been describedwhich fulfills the objects of the invention herein. It will beappreciated that various changes may be made by those skilled in the artwithout departing from the spirit and scope of the invention, which islimited only by the following claims.

What is claimed is:
 1. An apparatus comprising: a container capable ofreceiving a plurality of capacitive devices, one or more of thecapacitive devices having a first capacitor terminal and a secondcapacitor terminal; a cover mountable to the container, the covercomprising: a common cover terminal having at least one contactextending from the cover, one or more capacitor cover terminals, each ofthe one or more capacitor cover terminals having at least one contactextending from the cover, a first conductor electrically connectable tothe first capacitor terminal and one of the one or more capacitor coverterminals, a second conductor electrically connectable to the secondcapacitor terminal and the common cover terminal, and an insulationstructure associated with one of the one or more capacitor coverterminals; and a relay that controls opening and closing of contacts,wherein selected ones of the plurality of capacitive devices areconnected when the contacts are closed and the selected ones of theplurality of capacitive devices are disconnected when the contacts areopen.
 2. The apparatus of claim 1, wherein the insulation structure iscup shaped.
 3. The apparatus of claim 1, wherein one or more of thecapacitive devices provides at least one metalized film capacitor. 4.The apparatus of claim 3, wherein the at least one metalized film ispolypropylene metalized with zinc.
 5. The apparatus of claim 3, whereinthe at least one metalized film is about 4 microns or less in thickness.6. The apparatus of claim 1, wherein one or more of the plurality ofcapacitive devices has a capacitance value between about 48 and 112microfarads.
 7. The apparatus of claim 1, wherein the relay is anelectronic relay.
 8. The apparatus of claim 7, wherein the electronicrelay is sized to fit above the container.
 9. The apparatus of claim 1,wherein the relay is a control relay or a potential relay.
 10. Theapparatus of claim 1, wherein the plurality of capacitive devices have acombined capacitance value of about 296 microfarads.